In addition to Alexander's Macedonians, forces were
volunteered from various nations in the siege of Tyre. This is relevant because if the forces volunteered on their own, then they were acting as their own nations.

Arrian of Nicomedia (ancient historian): “[Support came from] Aradus… Byblus… Rhodes… Sidonian triremes [from Sidon],… From Soli and Mallus… from Lycia… Not long after, too, the kings of Cyprus put into Sidon with about one hundred and twenty ships, since they had heard of the defeat of Darius at Issus, and were terrified.” [The Anabasis of Alexander 19 (trans. by Chinnock, 2010)]

Tyre naturally saw Lycia, Sidon, Cyprus, etc. as
a multitude of nations, attacking her from different angles1, as did Alexander.2 This is relevant because the prophecy was a communication to Tyre.

Arrian of Nicomedia (ancient historian): “The Cyprians also sailed into the other harbour looking towards Sidon, …and made a speedy capture of the city on that side.” [The Anabasis of Alexander 18]

Alexander saw some of these submissive city-states as simply making a gesture to get on his good side; he knew each, given the opportunity, would turn on him just as quickly as they would and were turning on the Persian king before him. A nation's choosing to submit to the latest overlord's wishes need not involve their being subsumed into the overlord's nation (in this case, Macedon).